Probability I

Sample space




Events

1. An event is a subset of outcomes which satisfies certain conditions.
2. An event may or may not occur in an experiment. An event is possible if its elements are the elements of the sample space.
3. An impossible event is an empty set.


Probability of an event

1. The probability of an event is the ratio of the number of times the event occurs to the number of trials.
2. Probability of an event A
3. Probability of an event = 1 if the event is certain to happen.
4. Probability of an event = 0 if the event is impossible to happen.
5. Expected number of times an event will occur
= Probability of the event x number of trials.